Field of the Invention
The present invention relates to a method and an apparatus for controlling a damper clutch to prevent engine stall, and more particularly, to a method and an apparatus for controlling a damper clutch to prevent engine stall which can decide and correct when there is any error in control of a damper clutch in order to prevent engine stall.
Background Art
The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.
In general, the greatest fault of an automatic transmission is that mileage is lower than a manual transmission because the automatic transmission transmits driving power through the medium of a fluid. Internal loss of the automatic transmission is about 70% in loss by slip of the fluid of a torque converter, about 15% in loss by drive and about 15% in loss by sliding of a clutch or a band.
In order to solve the above-mentioned demerit of the automatic transmission, a damper clutch is provided to minimize a loss by slip, reduce fuel consumption and improve silence by directly and mechanically connecting a pump of a torque converter with a turbine at the time of reaching a predetermined vehicle speed or higher.
An operation area of the damper clutch is set according to the degree of opening of a throttle valve and vehicle speed. Moreover, the damper clutch is controlled in an off-line state at a low-stage or low-speed area to enhance acceleration power of a vehicle, but is controlled in a direct connection state at a directly connected area to enhance efficiency in transmission of power.
In the meantime, the damper clutch may generally cause troubles, such as disconnection/short circuit of a damper clutch control solenoid valve (DCCSV) or impossible release/connection at the time of mechanical damper release/connection command of the damper clutch.
Particularly, in relation with the latter, there is a problem in that a control signal of a duty command value or a current command value to command a direct connection of the damper clutch becomes wrong when a control logic is replaced or added to a damper clutch controller to control the damper clutch or when a worker makes a mistake in calibration.
However, such a prior art has several disadvantages in that engine stall may occur by the direct connection of the damper clutch directly after engine start or at the low-stage or low-speed area because there is no control logic to initialize the duty command value or the current command value when the duty command value or the current command value of the damper clutch is wrong and in that acceleration power is decreased due to the direct connection at an unintended area.